To foster automation of physical distribution, it becomes necessary to make it possible to read the descriptions of slips, etc., put on articles, etc., by a machine.
Hitherto, for this purpose, a bar code label corresponding to the description of each slip has been put on the slip.
However, to read the bar code label using a bar code reader, the bar code label and the bar code reader must be related to each other with respect to the given distance and the given direction with high accuracy and thus much labor is required and a bottleneck is produced for smoothing physical distribution. Further, since the amount of information that can be input to a bar code is small, the management range of physical distribution is also limited to a narrow district.
In recent years, a noncontact IC tag that can be read in a noncontact manner using an electromagnetic wave has been used. Since an electromagnetic wave is used as a read medium, when the noncontact IC tag is read, distance and directional restrictions are not much received and it is easy to reliably read the description of the noncontact IC tag.
Individual information of the article to be managed can be stored in the IC in the noncontact IC tag in a large capacity. Therefore, it is also made possible to use the storage function of the individual information as security information to identify the individual.
Usually, to use such a noncontact IC tag in a physical distribution management system, information in the noncontact IC tag is read using conveyor-type readers as shown in FIG. 17, gate-type readers as shown in FIG. 18, or the like.
More particularly, articles 100, 200, etc., on which noncontact IC tags 101 and 201 are put are transported with a conveyor 120, a forklift 220, or the like and are allowed to pass through the space between the readers 110 and 111 (FIG. 17) or between the readers 210 and 211 (FIG. 18).
At this time, the data in the noncontact IC tag 101, 201 is read through the readers 210 and 211 and is transmitted to a computer 130, 230 via a connection line 112, 212.
The computer 130, 230 is connected to a network in a mode as shown in a system configuration drawing of FIG. 19 to form a part of a physical distribution management system and thus the data read through the readers 210 and 211 and transmitted to the computer is used for management of the whole physical distribution process.
However, the conveyor-type readers 110 and 111 or the gate-type readers 210 and 211 are intended for checking the situation of each article when the article passes through the communication area between the readers, and cannot manage the state of the article until passage through the next readers after passage through the readers.
That is, the comings and goings of articles can be grasped, but the readers have no effect in managing the locations and the storage state of the inventory articles, tracking the transport route at the transporting time, or preventing an article mix-up, erroneous distribution, etc.; this is a problem.
As a method for solving the problem, a physical distribution management system for storing data in a noncontact IC tag put on an article in a wireless communication unit installed on a loading platform of a pallet, etc., loaded with the article as freight information when it passes through gate-type readers is proposed (refer to JPA-2002-154618).
The physical distribution management system uses the freight information for each pallet in the wireless communication unit for physical distribution management, thereby managing different articles in pallet units. Bluetooth is used for the wireless communication unit, whereby a communication distance of several meters is made possible and location management and transport route tracking of the articles are conducted.
However, management information concerning the storage state of freight on each pallet such as pulling out of articles in solid body units or adding of other articles after passage through gate-type readers, etc., cannot be grasped; this is a problem.
It is also difficult to conduct storage management for mixing articles in transporting, temporarily storing articles in the process of being transported, etc., and conduct location management in the outdoors, in a huge warehouse, etc.
Further, since articles need to be passed through conveyor-type readers or gate-type readers in carrying in and carrying out, the carrying-in and carrying-out paths are limited and freight is tied up in front of each reader; this is a problem.
On the other hand, as a general use method of a noncontact IC tag, data can be written into memory in the noncontact IC tag at each physical distribution site and can be used for physical distribution passage management of the article.
However, in the method in the related art using conveyor-type readers or gate-type readers, the data input at each site can be changed as desired and the data is poor in reliability as management data; this is a problem.
Further, in the physical distribution management system in the related art as described above, unless all traders involved in each step invest in readers and data in all traders is associated via a network as shown in FIG. 19, a complete physical distribution management system cannot be constructed; this is a problem.
Therefore, if a large effect produced by introducing a physical distribution system using noncontact IC tags cannot be expected, the cost burden on the traders becomes excessive and thus introducing a physical distribution system using noncontact IC tags is delayed; this is a problem.
Consequently, penetration of a reader/writer that can communicate with a noncontact IC tag does not increase and use of a noncontact IC tag does not grow; this is the current state of affairs.